1. Field of the invention
This invention relates to an active array substrate for a flat panel display (FPD), particularly to an active array substrate for a liquid crystal display, and is capable of lowering the probability of the phenomenon of “weak line” resulting from heavier load of a repair circuit.
2. Description of Related Art
FIG. 1A shows a schematic diagram of an active array substrate for a conventional flat panel display. As shown in FIG. 1A, a conventional active array substrate 1 includes a substrate 11, a plurality of scanning lines 12, a plurality of data lines 13, a plurality of first repair lines 14, a plurality of second repair lines 15, and a plurality of third repair lines 16. The substrate 11 has a display area 111. The scanning lines 12 and the data lines 13 are disposed on the substrate 11. In the display area 111, the scanning lines 12 and the data lines 13 are crossed and electrically separated from each other. On the other hand, the first repair lines 14 and the second repair lines 15 are located outside the display area 111. The first repair lines 14 and the second repair lines 15 cross with the data lines 13 on the upper area and the lower area outside the display area 111 respectively. Generally, the first repair lines 14 and the second repair lines 15 are not in electrical connection with the data lines 13. The third repair lines 16 are disposed along the right area outside the display area 111 and are respectively in electrical connection with the first repair lines 14 and the second repair lines 15. In addition, as shown in FIG. 1A, the active array substrate 1 for the conventional FPD is incorporated respectively with a plurality of data driver chips (not shown) and a plurality of scanning driver chips (not shown) by providing a plurality of first connecting pads 17 and a plurality of second connecting pads 18. Therefore, the data lines 13 are electrically connected to the data driver chips to receive data signals, and the scanning lines 12 are electrically connected to the scanning driver chips to receive scanning signals.
FIG. 1B is an enlarged schematic diagram of the manner of intersection of the first repair lines and the data lines of FIG. 1A. FIG. 1C is an enlarged schematic diagram illustrating the intersection of the second repair lines and the data lines of FIG. 1A. Referring to FIGS. 1A to 1C, as a representative data line 131 has a breach 132, laser illumination is used to weld an intersection portion 133 of the data line 131 and a representative first repair line 14 and to weld an intersection portion 134 of the data line 131 and a representative second repair line 15. And signals transmitted from the data driver chips (not shown) to thin film transistors (not shown) of pixels beneath the breach 132 is through a “repair line circuit”. The “repair line circuit” is constituted by the first repair line 14, a representative third repair line 16, the second repair line 15 and the data line 131 beneath the breach 132. Therefore, the pixels can be under control of the data driver chips (not shown).
However, the first repair line 14 and the second repair line 15 are respectively crossed through the data line 13 outside the upper area and the lower area of the display area 111. In other words, the first and second repair lines 14 and 15 are respectively crossed through each of the data lines 13. As the “repair line circuit” is in operation, due to capacitance occurring in the intersection portion of the first repair lines 14 and the data lines 13 and the intersection portion of the second repair lines 15 and the data lines 13, the loading of the “repair line circuit” will be increased. Therefore, though the thin film transistor of the pixel (not shown) beneath the breach 132 can be controlled, the response speed of the thin film transistor of the pixel beneath the breach 132 is slower than that of other thin film transistors. It results in an abnormal frame, and the phenomenon is called “weak line”.
Thus, in the industry, an active array substrate for use in a flat panel display and repair method thereof are required to reduce the probability of the “weak line” phenomenon due to heavy load of the repair circuit. Therefore, after repairing, response speed of the thin film transistor of the pixel is not decreased, and the frame on the flat panel display can be maintained normally.